Bidens campylotheca ssp. waihoiensis is an erect perennial herb in the Asteraceae (sunflower) family, woody at the base, 0.7 to 4 m (x to x ft) tall, with sprawling horizontal lateral branches. Leaves are pinnately compound and bi- or tri-pinnatifid, or bipinnately compound, 7 to 29 cm (x to x in) long. Flower heads are 5 to 20 in diffuse panicles or compound cymes terminating lateral branches only. Yellow ray and disk florets are often divergent so that flower heads have a loose, globose appearance. Achenes are brownish black, straight to curved, irregularly twisted or coiled, wingless or with narrow undulate wings. Subspecies waihoiensis with leaflets dissected into linear segments 0.4 to 1.5 cm (0.2 to 0.6 in) wide, achenes straight or slightly curved, undulate-winged, margins bristly, and awns 1 to 3 mm (0.04 to 0.1 in) long.